1. Field of the Invention
The present invention relates generally to a method and an apparatus for sending and receiving channel state information in network Multiple-Input Multiple-Output (MIMO) wireless communication systems, and more particularly, to a method and an apparatus for sending and receiving channel state information that transmit channel information to be divided into short-term channel information and long-term channel information and restoring full Channel State Information (CSI) in MIMO network wireless communication systems.
2. Description of the Related Art
A MIMO system has been suggested to provide data service of high speed and high equality in wireless communication where a transmitter and a receiver of the MIMO system have a plurality of antennas. Spatial processing is required in a transmitter and a receiver in MIMO technology. Accordingly, the transmitter and the receiver should have MIMO CSI between the transmitter and the receiver.
Specifically, the transmitter should have down link MIMO channel information from nT transmission antennas of a Base Transceiver Station (BTS) to nR reception antennas of an Access Terminal (AT) in a down link. Because a down link and an up link in a Frequency Division Multiplexing (FDM) system use different frequency domains, in order a BTS for having a down link CSI, a receiver should estimate a down link channel and feedback the estimated down link CSI to a transmitter. To feedback complete CSI to the transmitter, because transmission of much reverse link information is required, a user can use only minimum feedback information up to now.
As a result, to maximize system transmission capacity of a MIMO network, there is a need for research with respect to a feedback channel, a transceiver structure, and transmitting/receiving operations of technology transferring complete down link channel information to a transmitter using a limited amount of feedback information.